Conway Groups
The Automorphism Group 
of the Leech Lattice modulo a center of order two is called ``the''Conway group. There are 15 exceptional Conjugacy Classes of the Conway group. This group,combined with the Groups 
and 
obtained similarly from the Leech Lattice bystabilization of the 1-D and 2-D sublattices, are collectively called Conway groups. The Conway groups areSporadic Groups.
References
Wilson, R. A. ``ATLAS of Finite Group Representation.''http://for.mat.bham.ac.uk/atlas/html/contents.html#spo.
- Euler Characteristic
- Euler Constant
- Euler Curvature Formula
- Euler Differential Equation
- Euler Equation
- Euler Formula
- Euler Four-Square Identity
- Euler Graph
- Eulerian Circuit
- Eulerian Cycle
- Eulerian Integral of the First Kind
- Eulerian Integral of the Second Kind
- Eulerian Number
- Eulerian Trail
- Euler Identity
- Euler Integral
- Euler-Jacobi Pseudoprime
- Euler-Lagrange Derivative
- Euler-Lagrange Differential Equation
- Euler L-Function
- Euler Line
- Euler-Lucas Pseudoprime
- Euler-Maclaurin Integration Formulas
- Euler-Mascheroni Constant
- Euler-Mascheroni Integrals